SUPPRESSION OF BEAM-BREAKUP IN SELF-MODE-LOCKED TI-SAPPHIRE LASERS

We show that thermal aberration in optically pumped solid-state lasers can lead to the breakup of the beam profile. Kerr lensing present in the self-mode-locked regime tends to reduce the beam size in the laser material; such a beam is less sensitive to the thermal aberration, an d its shape becomes free of secondary lobes. The thermal aberration ha s also the effect of moving the optimal operation point for self-mode locking. Experimental results obtained with a Ti:sapphire laser suppor t our theoretical results.